Will Djokovic keep his place ahead of Federer for the semi-final?

At Roland-Garros, Roger Federer has yet to drop a set, having defeated Feliciano Lopez (6-3, 6-4, 7-6), Maxime Teixeira (6-3, 6-0, 6-2), Janko Tipsarevic (6-1, 6-4, 6-3), Stanislas Wawrinka (6-3, 6-2, 7-5), and Gaël Monfils (6-4, 6-3, 7-6) without too much difficulty. What will happen in the semi-final when he faces Novak Djokovic?

The Serb is currently the world number one, having won all 43 of his matches. Furthermore, he has already won seven titles in 2011 (Australian Open, Dubai, Indian Wells, Miami, Belgrade, Madrid, and Rome). If he reaches the French Open final, he will become world number one, surpassing Rafael Nadal of Spain.

Before Roland-Garros in 2011, Djokovic had had some rather frustrating performances, having won against Victor Hanescu after the Romanian retired in the 3rd set and having beaten Fabio Fognini in the quarter-finals, but following the latter's withdrawal.

In 21 encounters, Roger Federer has a significant advantage, leading 21 wins to 9. However, in 2011, he suffered three defeats against the Serb (the Australian Open, the semi-finals of the Indian Wells Masters, and the final of the Dubai tournament). This season, he has had a flawless run on clay, winning all three tournaments: Belgrade against Feliciano Lopez, Madrid against Rafael Nadal, and Rome, again against Rafael Nadal. All the experience and lessons Federer has accumulated will provide him with a solid foundation to secure victory against a formidable player like the Serb, as has been the case so far.

A clash of titans is brewing. The bets are on…